QS 3000w midmotor

[j bjork]

QS 4000 mid will power a Quantya next weeks. ASI 8000, 5.8kwh 20s battery.

lets see if we can reach 40kw

I am very interested in the result
It would be nice to know how the ASI compares to votol in sport mode when it comes to throttle response and low end power.
I don't know if the ASI has some kind of IPM optimization, on the votol the FW compensation seems to make pretty much difference.

 

[PITMIX]

Did you have a premature motor shaft wear problem? A friend only did 100km with his Qs 138 70h.

 

[eee291]

:lol:
TBH I'd just weld the sprocket on the shaft, always worked for me :wink:

 

[PITMIX]

I am using the 22T pulley with the Woodruff key and belt I have no problem. My friend noticed the wear issue from the start and he never exceeded 8kW with this motor :?
It looks like a manufacturing defect in the original pinion or a fragile motor shaft.
I have the impression that the new Qs 4kW uses a Woodruff wrench also with the 428 chain sprocket

 

[PITMIX]

:lol:
TBH I'd just weld the sprocket on the shaft, always worked for me :wink:

Why did you weld the pinion? you thought there was a risk that it would move? Yet you said you never had a problem.

 

[eee291]

Not on the QS 3K but on other motors like the Denzel.
I ended up welding the sprocket to the shaft because the key shredded itself a couple times, chewing up the shaft in the process. I've had no problems since then :lol:

 

[j bjork]

There is a lot of play with the Chinese sprockets. I have a little wear on my shaft, but not too bad yet.
Unfortunately good sprockets are only available in 11 tooth or bigger, but they fit perfectly on the shaft with no play.
They also take on the whole splines on the shaft, not just the outer mm or so like the Chinese ones.

I don't remember what they are called, but I have posted everything in my ktm build thread.

 

[PITMIX]

Thanks j Bjork

 

[j bjork]

You are welcome
If somebody has found good 10 tooth sprockets I am interested.

 

[PITMIX]

J bjork I find this :
[user_id=60898]
I have been looking at sprockets lately. My 10 tooth front sprocket is already pretty worn:

It also has play on the shaft, and I can see that it is wearing on the axle.

I tested this sprocket, it seems to be a very tight fit. I didn't fully mounted it, because it would take a little force. And I only borrowed the sprocket. However, that particular sprocket was not available in less than 13 tooth or something like that.

But I did find this one:

It seems to be the same size, and is at least available in 11 tooth. I want to gear down, not up :?
But I will try it at least, so I ordered a few.

I have also ordered a 80 tooth sprocket for the rear, but if I go with 11 tooth front it will not be much better than what I have now.
[/quote]

 

[Stevebequik]

Looks like you can get a water cooled version of the new 4kw 138 90h. Rated at 7.5kw continuous.
https://www.aliexpress.com/item/4001276167004.html

 

[AlphaZ]

Hello,

Here's my new motor test with my new battery

https://youtu.be/1kFfqVE8PKc

Enjoy

 

[PITMIX]

Very good AlphaZ ! :wink:

 

[Overclocker]

IMG_20200724_205930.jpg

Did you have a premature motor shaft wear problem? A friend only did 100km with his Qs 138 70h.

how prevalent is that issue? btw what chain is that, the sprocket must be narrow like #415H? probably why the shaft stripped like that

btw here's my QS 120 shaft. seems to be doing alright but this is a weaker motor

 

[PITMIX]

The problem arises from the pinions which have play on the motor shaft. Besides, Qs motor has modified the new 4kW motor with pinions fixed by a Woodruff key.

 

[Overclocker]

well the 20mm shaft is back with their new motor w/ built-in 2.35x gearbox

btw i do have some play


[youtube]H9PfBRnbbIM[/youtube]

 

[PITMIX]

the speed of rotation will be lower but the torque much stronger. Maybe they adjusted the diameter of the shaft better.

 

[Overclocker]

seems to be the same 20mm. let's hope they improved the metallurgy and heat treatment

 

[stan.distortion]

Play will certainly be the main cause but width wont be helping much either. Most (almost all) sprockets available for that spline are the same width as the teeth, some have a bossed centre for wider splines but they're few and far between. It's a weak point and I'd ordered a tapered shaft motor to avoid it but if only the splined shaft was available I'd cut down a 2nd sprocket to just a boss and weld it to a regular sprocket to get a double width spline. Might have to take down the width to get the circlip on but anything over is a big bonus.

Cush drives don't seem to be a high priority in many builds either and that seems to be causing some issues with shaft breakage. Most road bike wheels have substantial cush drive rubbers built into the rear hub but motorcross wheels generally have little or none, lacing an mx rim onto a road hub will add a fair amount to both cost and weight but could avoid bigger problems later.

 

[j bjork]

qsred.jpg

well the 20mm shaft is back with their new motor w/ built-in 2.35x gearbox

Is it available somewhere, or is there more info somewhere?
I saw something on facebook, but not much info except the gear ratio.

 

[SlowCo]

Is it available somewhere, or is there more info somewhere?

Yes, but I hope the price isn't for a single unit...:https://www.aliexpress.com/item/1005001515841817.html?spm=2114.12010612.8148356.2.41687d88T28V1M

 

[Overclocker]

qsred.jpg

well the 20mm shaft is back with their new motor w/ built-in 2.35x gearbox

Is it available somewhere, or is there more info somewhere?
I saw something on facebook, but not much info except the gear ratio.

$308. preorder 50% downpayment just email them. the aliexpress link just serves as an announcement, priced high just to make sure no one actually buys it :lol:

 

[j bjork]

Thanks, it should not be that far away if pre orders are possible.
It would be interesting to know what gears they are using, and how much abuse it can take.

I hope it is not max 10kw as they say on the ad.

 

[John in CR]

Someone need to tell them to harden the splined part of those shafts. Both the premature wear and loose fit are totally unacceptable, and welding the sprocket to the shaft as the only real fix is crazy. Electrics need to be built with a 10yr mininum life requirement unless someone has inside info that a cheap room temp superconductor is going to mass production for sooner.

Thanks for the posts, I was planning on placing a small order of 10 or so of these, but now no f'ing way as that shaft means no way you can use regen.

 

[HrKlev]

The loose fit is in the sprocket. I saw j bjorks thread and also ordered a JT sprocket (for some suzuki 85cc dirt bike, was it?). It fits perfectly. On mine, the wear was on the old sprocket for most of the part after 1000km, motor was fine. But yeah, I agree it is definately not hardened like it should.

Looks like they offer a 14t sprocket that fits on the conical version with a key. Should be better if you can get away with a 14t. Will have to make custom sprocket whenever it wears out, though...